The present invention relates to an LED lamp having light-emitting junctions arranged in a three-dimensional array.
U.S. Pat. No. 5,998,925 discloses a light emitting device which comprises a semi-conductor light emitting layer embedded in a transparent globe. A fluorescent material covers the semi-conductor layer to receive the emitted light for transmission at a different wavelength, i.e. in a predetermined colour.
To increase the intensity of the light output, additional semi-conductor devices may be added, such as shown in U.S. Pat. No. 5,289,082, which discloses an LED lamp having a plurality of semi-conductive chips mounted in a translucent body. Each chip emits a discrete light pattern, however, and that may be undesirable if the light from the lamp is desired to have an appearance of emitting from a single, point-like light source. In U.S. Pat. No. 5,289,082, the discrete light outputs are combined and focussed, by specific shaping of the body to produce an overall light output having a required illumination pattern.
GB 2311126 discloses a comparatively large scale light source which includes an array of separately mounted light emitting diodes which appear to have respective leads hardwired to a planar conductor. The diodes are encapsulated by a lens which is used to focus the light from the array.
The present invention seeks to provide an alternative form of LED lamp which can provide high intensity output by utilising a plurality of light emitting diodes, whilst maintaining the appearance of a substantially point source of illumination.
In accordance with the present invention, there is provided a lamp including a plurality of semi-conductor light emitting junctions with a common layer of fluorescent material arranged thereover, wherein the junctions are provided in a three-dimensional array.
In another aspect, there is provided a lamp including a plurality of semi-conductor light emitting junctions with a common layer of fluorescent material arranged thereover, wherein the junctions are mounted to a curved support structure so as to be arranged substantially on an imaginary spheroid surface.
The common layer of fluorescent material can serve to receive light from adjacent junctions and transmit same in a distributed fashion, so that the resultant light appears, to the naked eye, to be emanating from a single point source of illumination. Further, the layer can be applied over the junctions in a single step, and that in turn can lead to substantial simplification in the procedure for constructing the lamp, as compared to formation of the discrete chips of U.S. Pat. No. 5,289,082, which would need to be individually constructed or produced using additional steps of masking and etching.
Preferably, the lamp includes a globe portion and the junctions are embedded within the globe portion so that the lamp is formed as a unitary structure.
Preferably, the junctions are mounted to, and electrically coupled with, at least one curved conductor.
In another broad aspect, the invention provides a lamp including a plurality of light emitting junctions mounted to at least one curved conductor so as to adopt a three-dimensional array, wherein the lamp includes a common layer of fluorescent material over at least adjacent junctions.
In yet another aspect, there is provided a lamp including a plurality of light emitting junctions mounted to at least one curved conductor so as to adopt a three-dimensional array, wherein the at least one curved conductor includes a recess for receipt of a respective one of the junctions.
Preferably, the at least one curved conductor is configured such that junctions are arranged substantially on an imaginary spheroid surface.
The curved configuration of the conductors and, in particular, the junctions being arranged on a substantially spheroid imaginary surface provides an advantage that the overall light generated by the lamp will appear to be coming from a generally singular small spherical or point source.
Preferably, the recess has side walls which function as an optical guide for controlling the direction of light transmission and/or the angle of divergence.
Preferably, the lamp includes a globe portion, with the junctions and the at least one curved conductor being embedded within the globe portion so that the lamp is formed as a unitary structure.
Preferably, the lamp includes a lens adapted to fit with the globe portion, and configured to shape the light emitted from the globe portion into a predetermined pattern.